The invention discloses a device and a method based on an MEMS gyroscope, for gun barrel speed measurement. The device comprises a control terminal, a downloading communication module, a control module, a communication module, the MEMS gyroscope, a relay and a power supply conversion module, wherein the control terminal is used for setting control parameters, and analyzing a gun barrel speed according to the measurement result fed back by the MEMS gyroscope; the downloading communication module is used for downloading the control parameters of the control terminal, and transmitting the controlparameters to the control module; the control module is used for generating control instructions for the MEMS gyroscope and the relay according to the control parameters; the communication module isused for realizing signal interaction between the control module and the MEMS gyroscope, and carrying out control instruction sending and measurement result feedback; the relay is used for adjusting aspeed measurement direction; the MEMS gyroscope is used for measuring the angular speed of a gun; and the power supply conversion module is used for realizing voltage conversion, and supplying powerto the control module, the relay and the MEMS gyroscope. According to the device and the method, the volume of the speed measurement device is reduced, and the test stability and accuracy are improved.